python 提取和分割超大txt文件到csv文件

import csv
import os

NEW_CSV = ".\\generate"

def trans_format(txt_path=""):
    if os.path.exists(txt_path):

        with open(txt_path, encoding='utf-8') as f:
            txt_row = "123"
            count = 0
            index = 0
            while txt_row:
                txt_row = f.readline()
                txt_row_list = txt_row.split('\t')

                open_csv = open(NEW_CSV+str(count)+'.csv', 'a+',encoding='utf-8')
                csv_writer = csv.writer(open_csv)
                csv_writer.writerow(txt_row_list)
                open_csv.close()
                index += 1
                if (index % 10000 == 0):
                    count = count+1
    else:
        print('can not transform')
    return

if __name__ == "__main__":
    trans_format(".\\two")